The present invention relates essentially to an apparatus with means of self-displacement of its advance in the interior of a duct or the like, particularly for remote inspection and/or treatment and/or tubing thereof.
There are already known various self-displacing or self-propelling apparatus for remote internal inspection of ducts and/or treatment thereof.
For example, French Pat. No. 1 583 501 discloses a self-propelling truck capable of drawing a trailer in the interior of a duct with a view to taking X-ray photographs of the circular butt-welds joinint the tubes together. This truck includes a propelling device with driving wheels mounted at the top of a jointed pantograph.
Such a self-propelling truck can be used only in large-diameter ducts for it poorly lends itself to miniaturization. Furthermore, it can generally enter only relatively clean ducts. For example, if the duct wall has various viscous or sticky deposits on it, such as for example tar, such a self-propelling truck, owing to its design, cannot advance in the duct, due particularly to its deficiency in tractive force.
Also, French patent application No. 71 37 060 discloses a compact vehicle for examining transporting and distributing conduits whose advance is ensured by the presence of driving wheels and the design of which is complex in order, particularly, to allow the apparatus to be directed in the interior of the duct. Also this vehicle is limited in tractive force.
Another example of such a type of apparatus is disclosed in French patent application No. 76 05 237 (publication No. 2 342 455), the advance of which is ensured by a wheel and V-belt system. Likewise, this device cannot overcome all the obstacles and is limited in tractive force.
To sum up the foregoing, the prior art in this technical field relates essentially to apparatus with means of self-propulsion or self-displacement for their advance in the interior of ducts, particularly for their remote inspection and/or treatment in case the said ducts are perfectly clean and without solid extraneous matter.
But ducts are often polluted or soiled and contain solid extraneous matter, particularly sticky matter such as for example tar, so that considerable tractive forces are required which the presently known trucks cannot produce. Furthermore, all the apparatus of the prior art are of complex design making any considerable miniaturization thereof practically impossible and thus preventing their use in small-diameter ducts.